The present disclosure relates generally to measuring fluid properties and, more particularly, to an apparatus and method to test a property of a fluid.
Drilling fluids are commonly used when drilling a wellbore which penetrates one or more subterranean earth formations. The shear strength of a drilling fluid is an important drilling fluid property, the knowledge of which may indicate drilling fluid that will be stable in a wellbore after a long period of time. Conventional methods of determining shear strength may involve the use of a shear tube on top of a column of test fluid. For a fragile or low shear strength test fluid, the weight of the shear tube may be sufficient for the shear tube to break the surface of the test fluid and move into the column. However, if the test fluid surface holds the weight of the shear tube, weight is incrementally added to the shear tube to ensure movement of the shear tube past the surface and into the column of test fluid. Impact loading from the process of adding weight to the shear tube can vary the measurement reading. In general, conventional methods of determining shear strength are prone to variability in measurements and human error; measurement repeatability and accuracy is difficult to achieve.
Needed in the art are apparatuses and methods to measure properties of a fluid that are more reliable and easier to implement, and that enable greater repeatability and accuracy.